The present invention relates to a fingerprint input device used in a fingerprint identification system which carries out identification of a fingerprint to thereby indentify personnel by means of his fingerprint.
As disclosed in the U.S. Pat. No. 4,310,827, the fingerprint input device produces a two-dimensional photoelectrically converted image of an impressed fingerprint in the form of the streaked pattern and supplies it to an identifying processor of the fingerprint identification system which also comprises filing means for storing a plurality of minutiae lists each of which represents the feature points of a registered fingerprint. The processor compares the image with the plurality of minutiae lists or one of the minutiae lists selected by the user, and judges whether the impressed fingerprint is identical to the registered one or not.
The Japanese Patent Disclosures Nos. 69300/1979 and 85600/1979 described a fingerprint input device capable of directly scanning the front end of the finger put on a surface of a glass plate or a prism to obtain the digital image of the streaked pattern of the fingerprint. print. This input device is advantageous in that it does not require a recording medium, such as a paper card, on which the finger with ink is impressed to transfer the ink. The streaked pattern of the fingerprint can be read out without the finger being made dirty.
However, the conventional fingerprint input device may misread the streaked pattern of the fingerprint, because the furface ofthe finger is covered its secretion such as sweat and grease and the secretion adheres to the surface of the glass plate or the prism every time the finger is impressed thereon. Further, the dirt on the finger-impressing surface makes the user uncomfortable.